1. Field of the Invention
The present invention relates to an automatic return machine for empty containers and, more particularly, is concerned with an automatic empty container return machine equipped with a self-cleaning arrangement for performance of cleaning of the machine.
2. Description of the Prior Art
In German patent document No. DE 195 08 388 A1, there is disclosed a system for processing reusables which employs an automatic return machine for processing reusable containers, in particular, reusable cups. After consuming a drink, a consumer supplies the used cup to the automatic return machine in which the cup is tested for system conformity. If the cup is detected as being within the scope of the reusables system, return of the cup deposit money to the consumer takes place. The automatic return machine places such reusable cups in magazine type tubes or cases which are then transported to a separate service center. At the separate service center, the reusable cups are transported by a conveyor through a rinsing station equipped with spray nozzles and a drying device equipped with hot-air fans where the cleaning and drying of the reusable cups takes place. The cleaned and dried reusable cups are subsequently collected and transported back to automatic vending machines for reuse with drinks dispensed from such machines.
In European patent document No. EP 0 442 027 A2, there is disclosed an arrangement for the recovery of recyclable material from disposable packaging, in particular, disposable bowls made of aluminum or synthetic material. The disposable bowls traverse a conveying stage in which they are cleaned by spray jets from above and below. After traversing the cleaning stage, the disposable bowls arrive at a compression station where their volume is significantly reduced. The compacted disposable bowls subsequently fall into a collection container in order to be supplied to a recycling process.
In European patent document No. EP 0 774 738 A2, there is disclosed a device for treating glasses, cups and the like. This treating device corresponds substantially to the reusables processing system of the abovecited German patent document No. DE 195 08 388 A1, with the difference being that here the cleaning stage for used drink containers is integrated into the device and thus is not placed separately from it.
Other automatic return machines for empty containers of the type relevant to the present invention herein are known, for example, from the following publications: WIPO patent document Nos. WO 93/25981 and WO 93/03460; European patent document Nos. 0 561 148 B1 and 0 612 046 A1; German patent document Nos. DE 43 18 388, DE 44 43 406, DE 36 05 921, DE 196 13 099 A1, DE 37 15 815 A1, DE 93 21 439 U1 and DE Gbm 73 12 603; U.S. Pat. No. 5,085,308; and U.K. patent document no. GB1 552 927. These automatic machines are primarily employed in central markets, department stores or drink markets and make possible the automatic return of empty containers such as bottles and cases of bottles, cans, cups, bowls, etc.
Each of these machines comprises at least one input unit, via which the individual empty containers are supplied in either standing or lying condition or also in empty container cases for further processing. Depending on the structure of the automatic machine, an isolating unit can succeed the input unit, in which containers inserted individually are spaced apart from one another before they pass through the detection unit. These detection units work with mechanical sensors, light barriers, laser arrangements, camera measuring technique, etc. and serve for acquiring the type of a particular container. If a container is detected as not belonging to the return assortment class it is sorted out in a sorting unit and supplied to, for example, a return chute or a collection container for such containers. In the event of deposit-due empty containers, apart from the qualitative acquisition, in the detection unit a quantitative acquisition of the containers takes place. These data are supplied to a control unit which calculates the deposit and initiates, for example, the output of a deposit coupon. At the end of the processing, the containers or also the container cases are transported out of the automatic machine into an output unit and conducted to a collection site belonging to the logistics system for empty containers.
In the automatic machine, transport stages are provided on which the containers are conveyed from unit to unit. The transport stages can be, for example, conveyor belts, slides, chutes and gripper arms.
Since, as a rule, the empty containers contain residual liquids, which can flow out during the handling of the empty containers in the automatic return machine, after a certain length of operation heavy contaminations of the processing units, transport stages, sensors, etc. can occur which impair the functional capabilities of the automatic return machine. According to the prior art, the automatic return machines are therefore manually cleaned at specific time intervals. This is very expensive and also difficult given the cramped conditions of space in the automatic return machine, such that the quality of the cleaning suffers. Moreover, during this cleaning activity, installations in the automatic return machine could be damages.
The present invention overcomes the aforementioned problems by providing an automatic return machine of the above-stated type being equipped with a cleaning arrangement for performance of self-cleaning of the automatic return machine, which cleaning arrangement is integrated into the machine. The cleaning arrangement is provided constructionally with the machine so that even sites normally difficult to access can be reached. Problems due to cramped space are eliminated since the cleaning arrangement is already disposed at its intended location. Such prepositioning of the cleaning arrangement on the machine permits optimal and efficient cleaning of the machine and avoidance of the type of damage that is possible with manual cleaning. In addition, working time is saved since the automatic return machine, in effect, cleans itself.
The activation of the self-cleaning arrangement of the automatic return machine can be realized in several different ways. For one, fixed cleaning intervals can be provided and the invention, in connection with a time circuit, offers the option of scheduling the cleaning at a time which is outside of normal working hours, for example, during nighttime hours.
Also possible is cleaning as needed, wherein the degree of contamination can be determined by manual inspection or also, in an advantageous implementation of the present invention, automatically through sensors. The data sensed by the sensors can be transferred to a central control unit of the machine which, at a predetermined degree of contamination, stops the normal operation of the machine and initiates the self-cleaning process. If several machines are available in a supermarket or the like, the consequences of placing a machine out of operation can be managed by switching over to another machine so that the operation of the self-cleaning arrangement can take place immediately on the contaminated machine. Otherwise, given the corresponding programming, the operation of the self-cleaning arrangement can be offset in time, for example, by being shifted into nighttime hours.
In further implementation of the present invention, the cleaning arrangement comprises nozzles to act upon the surfaces to be cleaned with a cleaning medium, wherein additionally brushes can be provided which rest in contact on the surfaces to be cleaned and can be moved translationally, rotationally and/or oscillatingly or can also stand still if the surfaces, for example, of a conveyor belt are guided past them. The cleaning medium is conducted via the nozzles at low- or high-pressure onto the parts to be cleaned such that contamination is rinsed off, with available brushes supporting this cleaning process. Possible cleaning media are, as examples, water or other liquids in cold or heated condition, mixtures of water and cold-cleaning agents, liquid mist with ultrasound turbulence and hot steam.
It is further of advantage if the parts to be cleaned are provided with a special surface coating, which ensures low adhesion of dust and dirt particles, for example, coatings which are applied by means of nanotechnology. For the complete removal of liquid residues, fans can be employed which blow warm or cold air onto the parts to be cleaned.
To protect sensitive components, for example electronic components, in further implementation of the invention it is of advantage if the areas of the automatic return machine to be cleaned are encapsulated by a tubular envelope to screen off remaining areas where sensitive components may be located such that these components in the remaining areas do not come into contact with the cleaning medium and dissolved dirt particles. In order not to impair the functional capability of light barriers, optical sensors and image detection devices, the encapsulating envelope, within the range of effectiveness of these devices, is implemented to be light-transmissive.
In an embodiment of the invention, the self-cleaning arrangement also comprises collecting tubs for the cleaning medium and removed dirt are disposed below the areas to be cleaned. It is useful if these collecting tubs are provided as an integral part of the encapsulating envelope enclosing the areas to be cleaned, such as a lower closure of thereof. Lastly, it is reasonable to provide the collecting tubs with a drain via which the contaminated cleaning medium can be drained off and supplied, for example, to a reprocessing system.
These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.